The invention concerns an operating device for a gearbox.
This type of operating device is already known from international patent application WO 95/16869.
The above describes an operating device with single-shaft actuation, incorporating a shift rail which can be displaced in parallel to the gear axes, this shift rail being arranged in a transmission housing. The shift rail carries coupling devices which form a link between the shift rail and the shift forks of the respective gear to be engaged. At the same time, the shift forks of the gears not to be engaged are blocked.
This type of operating device is problematic, since it has no facility provided for holding the desired gear in its engaged position once it has been engaged.
In addition, EP 0 395 241 also concerns an operating device with single-shaft actuation, incorporating a facility on the shaft rail to indicate axial movement of the shift rail relative to the housing, this axial movement being from a neutral position to an axially different position which represents an engaged gear.
This operating device has no means provided for blocking an engaged gear in its engaged position. By the same token, the above described means for determining axial movement are means which have to be arranged on the shift rail together with the shift forks, thus increasing assembly expenditure and costs.
The present invention is, therefore, based on the tasks of further developing the operating device described in WO 95/16869 and avoiding additional expenditures.